Op 2020-10-18 om 23:03 schreef Jonas Maebe via fpc-devel:
>//>>>/I’ve been able to create a cross compiler using the guidance and some />>>/additional information. But I’ve been unable to create the proper FPC />>>/startup code (prt0.as) needed. />>>//>>>/Any help would be appreciated. />>/I believe these files are generally created by disassembling the />>/system's crt1.o (objdump -d) and then changing the call(s) to the libc />>/intialisation code with calls to the FPC RTL intialisation code. />Afaik mostly gcc -S. Trunk SVN also contains an untested and incomplete
attempt at translating the C startup files to pascal.
Thanks!
I think I maybe in over my head on this. I've taken a look and now I'm not sure what the issue is. The segfault occurs in the FPC RTL initiazation code (see backtrace below).
Any ideas?
# gdb ./ppcppc64 ppcppc64.core
GNU gdb (GDB) 8.3 [GDB v8.3 for FreeBSD]
Copyright (C) 2019 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "powerpc64-portbld-freebsd12.0". Type "show configuration" for configuration details. For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"... Reading symbols from ./ppcppc64...
warning: core file may not match specified executable file. [New LWP 100454]
Core was generated by `./ppcppc64'.
Program terminated with signal SIGSEGV, Segmentation fault. #0 0x7c0802a6fbe1fff8 in ?? ()
(gdb) backtrace
#0 0x7c0802a6fbe1fff8 in ?? ()
#1 0x000000001001fed8 in $fpc_initializeunits () at ../inc/system.inc:969 #2 0x0000000010000720 in $main () at pp.pas:256
(gdb) disass
No function contains program counter for selected frame. (gdb) frame 1
#1 0x000000001001fed8 in $fpc_initializeunits () at ../inc/system.inc:969 969 Procs[i].InitProc();
(gdb) disass
Dump of assembler code for function $fpc_initializeunits: 0x000000001001fe60 <+0>: mflr r0
0x000000001001fe64 <+4>: std r31,-8(r1)
0x000000001001fe68 <+8>: std r30,-16(r1)
0x000000001001fe6c <+12>: std r29,-24(r1)
0x000000001001fe70 <+16>: std r28,-32(r1)
0x000000001001fe74 <+20>: std r0,16(r1)
0x000000001001fe78 <+24>: stdu r1,-128(r1)
0x000000001001fe7c <+28>: bl 0x10002768 <fpc_cpuinit> 0x000000001001fe80 <+32>: nop
0x000000001001fe84 <+36>: addi r3,r2,15080
0x000000001001fe88 <+40>: ld r28,0(r3)
0x000000001001fe8c <+44>: cmpldi r28,1
0x000000001001fe90 <+48>: blt 0x1001feec <$fpc_initializeunits+140> 0x000000001001fe94 <+52>: li r31,0
0x000000001001fe98 <+56>: addi r3,r31,1
0x000000001001fe9c <+60>: mr r31,r3
0x000000001001fea0 <+64>: rldicr r4,r31,4,59
0x000000001001fea4 <+68>: addi r3,r2,15080
0x000000001001fea8 <+72>: ldx r3,r4,r3
0x000000001001feac <+76>: cmpldi r3,0
0x000000001001feb0 <+80>: beq 0x1001fedc <$fpc_initializeunits+124> 0x000000001001feb4 <+84>: rldicr r4,r31,4,59
0x000000001001feb8 <+88>: addi r3,r2,15080
0x000000001001febc <+92>: ldx r29,r4,r3
0x000000001001fec0 <+96>: ld r30,0(r29)
0x000000001001fec4 <+100>: std r2,40(r1)
0x000000001001fec8 <+104>: mtctr r30
0x000000001001fecc <+108>: ld r2,8(r29)
0x000000001001fed0 <+112>: ld r11,16(r29)
0x000000001001fed4 <+116>: bctrl
=> 0x000000001001fed8 <+120>: ld r2,40(r1)
0x000000001001fedc <+124>: addi r3,r2,15080
0x000000001001fee0 <+128>: std r31,8(r3)
0x000000001001fee4 <+132>: cmpld r31,r28
0x000000001001fee8 <+136>: blt 0x1001fe98 <$fpc_initializeunits+56> 0x000000001001feec <+140>: addi r3,r2,18272
0x000000001001fef0 <+144>: ld r3,0(r3)
0x000000001001fef4 <+148>: cmpldi r3,0
0x000000001001fef8 <+152>: beq 0x1001ff20 <$fpc_initializeunits+192> 0x000000001001fefc <+156>: addi r3,r2,18272
0x000000001001ff00 <+160>: ld r31,0(r3)
0x000000001001ff04 <+164>: ld r30,0(r31)
0x000000001001ff08 <+168>: std r2,40(r1)
0x000000001001ff0c <+172>: mtctr r30
0x000000001001ff10 <+176>: ld r2,8(r31)
0x000000001001ff14 <+180>: ld r11,16(r31)
0x000000001001ff18 <+184>: bctrl
0x000000001001ff1c <+188>: ld r2,40(r1)
0x000000001001ff20 <+192>: addi r1,r1,128
0x000000001001ff24 <+196>: ld r31,-8(r1)
0x000000001001ff28 <+200>: ld r30,-16(r1)
0x000000001001ff2c <+204>: ld r29,-24(r1)
0x000000001001ff30 <+208>: ld r28,-32(r1)
0x000000001001ff34 <+212>: ld r0,16(r1)
0x000000001001ff38 <+216>: mtlr r0
0x000000001001ff3c <+220>: blr
End of assembler dump.
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